This invention utilizes the age-old science of composting to volatilize and pasteurize animal tissues, some of which may be diseased and potentially pathogenic to humans. The process of this invention renders these animal tissues and manure safe and in fact suitable for use as a beneficial soil amendment. Concerns about large-scale pollution of water and soil by industry practices in areas like chicken and fish production demand workable solutions. Much of this waste is presently being cast directly into these waters and soil, making a serious threat to the safety of groundwater, air quality, soil, and fish and game.
Heretofore, all composting has been designed and practiced to provide the highest possible end product of organic fertilizer. The invention instead modifies and utilizes these established composting principles to achieve the primary goal of the safe disposal of animal wastes. The compost end product of this process is still of value, but the precise constituents are not of primary importance.
The past prior art is described in part in the very comprehensive study The Complete Book of Composting, published by Rodale Books, Inc., Emmaus, Pa., June 1974. Without exception, the composting devices and processes described in the history of this science have been designed to regulate the putrefaction of organic wastes to the end that nitrogen be fixed in the soil and compost. This is required to make the best organic fertilizer.
This science was first systematized by Sir Albert Howard in 1925-35 in India. He tested a layered pile, about 1.5 meters high, of garbage, animal wastes, sewage sludge, straw and leaves, turning it over twice in a 3 month composting period. In 1981, James A. Merkel, formerly Associate Professor, Department of Agricultural Engineering, University of Maryland, stated, in his book Managing Livestock Wastes, that there were two existing composting systems: first, enclosed digesters and secondly, windrows. He said: "enclosed digesters require a high capital investment and utilize a great deal of energy." This comment characterizes almost all of the existing patented prior art. Windrows he described as "nothing more than elongated piles that are turned periodically to aerate the organic wastes." Such a system in most climates with rainfall would require a large shed type roofed structure.
Rapidly growing awareness of the environmental pollution caused by the various agricultural waste disposal practices has created a new interest in the possible use of composting as one solution to these problems. Recent research at the Department of Poultry science, University of Maryland, Princess Anne, Md.; the University of Delaware College of Agriculture Science, Agricultural Experiment Station, Cooperative Extension, Newark, Del.; and Cornell University Department of Agriculture Engineering, Cornell Cooperative Extension, Rochester, N.Y. has resulted in the development of physical facilities and processes in pilot projects to compost chicken carcasses. These prototypes are now being proposed for massive replication wherever disposal of chicken carcasses poses a problem.
A comparison of the construction details of the Maryland, Delaware and Cornell pilot projects and the Rodale history clearly demonstrates the fact that the newer versions have borrowed directly from the older composting principles. These details include: 1) a "bin" concept (roughly 2.44 meters by 1.52 meters) contained by four walls that facilitate compost piling to a depth of 0.9 meters or thereabouts; 2) "layering" technique specifying straw, dead birds and "manure" (probably broiler litter--a combination of manure and sawdust) in alternate applications; and 3) open to the air on top of the pile. This is the main source of oxygen for the necessary aerobic decomposition.
This repetition of the historic details and practices of organic composting in an attempt to dispose of animal wastes has led to certain inefficiencies and complications. These include: first, the deficiency of adequate oxygen to support aerobic decomposition, particularly in the center of the pile. This has created the necessity, as stipulated in the Maryland and Delaware procedures, to "turn" (aerate) the pile with a front end loader machine once or twice in the process. This is necessary because of the development of anaerobic "pockets" of material deep in the pile that must be mechanically exposed to air in order to convert this unwanted bacteria into aerobic.
The second complication is in the "layering" process that utilizes straw in an attempt to conduct air to the center of the pile. This could be problematical in that the straw can become compressed and water-logged and not facilitate the flow of air. Further, this material may be a deterrent to the process by being extremely slow in breaking down in the composting process.
The third question about the Maryland and Delaware designs is that in being open at the top there does not seem to be a security against raids by dogs and varmints. In the very likely event that parts of animal carcasses are exposed in the pile, this could attract a variety of domesticated and wild animals to raid the pile.
Lastly, these pilot projects entail a costly, customized construction for each poultry operation. This includes a concrete floor, a structural frame and roof and treated lumber sidewalls. The cost of these structures are admittedly a deterrent in reaching the desired goal of wide-spread composting of animal wastes in an effort to clean-up the environment.